This standard specifies requirements for clothing capable of signalling the user's presence visually, intended to provide conspicuity of the user in hazardous situations under any light condition by day and under illumination by vehicle headlights in the dark. Performance requirements are included for colour and retroreflection as well as for the minimum areas and for the disposition of the materials. Test methods ensure that a minimum level of protection is maintained when the garments are subjected to care procedures.